FWIW to clear up some confusion - our launch scripts turns on KHR_no_error for WOTC for the extra performance.
See /path/to/install/dir/XCOM2WotC/config/extra-environment.sh:2
export MESA_NO_ERROR=1
I'll take a look and see if we're hitting a GL error at this stage.

It appears some errors slipped through.
Example:
[GL_DEBUG] Error message from OpenGL API call with id 1281: GL_INVALID_VALUE error generated. <index> out of range.
We'll handle this, I'd think it should be safe to assume this is an application bug. From what I understand using a KHR_no_error context is a trust handshake that you won't trigger any error states.

(In reply to Marc Di Luzio from comment #4)
> FWIW to clear up some confusion - our launch scripts turns on KHR_no_error
> for WOTC for the extra performance.
>
> See /path/to/install/dir/XCOM2WotC/config/extra-environment.sh:2
> export MESA_NO_ERROR=1
>
> I'll take a look and see if we're hitting a GL error at this stage.
O(In reply to Marc Di Luzio from comment #5)
> It appears some errors slipped through.
>
> Example:
> [GL_DEBUG] Error message from OpenGL API call with id 1281: GL_INVALID_VALUE
> error generated. <index> out of range.
>
> We'll handle this, I'd think it should be safe to assume this is an
> application bug. From what I understand using a KHR_no_error context is a
> trust handshake that you won't trigger any error states.
Thanks for confirming. Making as resolved.